E2F-1 Recombinant Rabbit mAb (S-2580-78)

E2F-1 is a 437-amino-acid transcription factor that sits at the apex of cell-cycle control, binding as a heterodimer with DP-1 to the consensus TTTCCCGC element in promoters of genes encoding S-phase regulators such as cyclin E, cyclin A and DNA polymerase-α; its activity is restrained in G0/G1 by direct association with the tumor-suppressor Rb, and upon mitogenic phosphorylation of Rb by cyclin-D-dependent kinases E2F-1 is liberated to activate transcription, while DNA damage triggers ATM/ATR-mediated phosphorylation and stabilization of E2F-1, converting it into a potent inducer of p53-independent apoptosis via transcriptional up-regulation of p73, Apaf-1 and caspases; accordingly, E2F-1 acts as both a canonical driver of proliferation and, under stress, a guardian against oncogenic transformation, and its gene is amplified or overexpressed in several human cancers yet germ-line polymorphisms that reduce E2F-1 levels are linked to increased lymphoma risk, illustrating the delicate balance of E2F-1’s dualistic role in life and death decisions of the cell.